The official Keighley Cougars website was last night hacked by a pro-Isis group.
Anti-terrorism police are investigating after the site was replaced with hateful messages and graphic images.
A message posted on the club’s Twitter account said: “Apologies, the website has been hacked. The developers are working on it. Will let you know when it’s back up and running.”
A spokesman for West Yorkshire police said: “We are aware of this incident and have now passed it to our counter-terrorism unit. We will work with the club in relation to this and are making enquiries.”
The website is now functioning as normal.